epaper_nametag/cable_guide.scad

// Waveshare 2.13" e-Paper HAT (B) — ESP32 Nametag Case
// Display slides in from X−; FPC routes through internal 180° bend guide at X+

// --- Display Dimensions (landscape: portrait rotated 90°) ---
DISP_W = 59.20;   // overall width  (X) — portrait height
DISP_D = 29.20;   // overall depth  (Y) — portrait width
DISP_T = 1.0;     // thickness      (Z)

// --- Active (Visible) Area ---
ACT_W  = 48.55;   // active area width (X) — portrait AA height
ACT_D  = 23.71;   // active area depth (Y) — portrait AA width

// Border offsets from display edge to active area:
//   X-: portrait top border  ≈ 1.95 mm  (open/entry side)
//   X+: portrait FPC border  ≈ 8.70 mm  (closed/backstop; FPC exits here)
//   Y±: symmetric            ≈ 2.75 mm  each side
ACT_X_OFFSET = 1.95;
ACT_Y_OFFSET = 2.75;

// --- FPC Cable (exits X+ side of display) ---
FPC_W   = 12.5;
FPC_T   = 0.3;
FPC_LEN = 20.0;   // visualization length of hanging tail

// --- FPC Bend Guide ---
BEND_R    = 2.0;   // inner bend radius (mm)
BEND_WALL = 1.5;   // wall thickness around channel (mm)

// --- FPC Excess-Cable Pocket (under display floor) ---
FPC_POCKET_D = 0.75;  // depth below display floor (Z), slip-fit with assembly clearance
FPC_POCKET_L = 20.0;  // length running toward X− from the X+ cavity wall

// --- Resin Drain Holes (Z− face, under bend guide arc bottom) ---
DRAIN_HOLES  = true;  // enable drain holes for SLA printing
DRAIN_D      = 3.0;   // hole diameter (mm)
DRAIN_MARGIN = 1.0;   // clearance from FPC cable corner to hole edge (mm)

// --- Case Parameters ---
WALL       = 4.2;   // = BEND_WALL + 2*BEND_R − DISP_T − TOL: keeps exactly BEND_WALL below channel
LIP        = 1.5;   // front bezel lip thickness (Z)
TOL        = 0.3;   // per-side display clearance
CHAM       = 1.0;
CHAM_ANGLE = 60;
CORNER_R   = 2.5;
X_PAD      = 0;     // extra bezel thickness added at X− (entry) end

// --- Magnetic Strip Pocket (back face) ---
MAG_L     = 1.772 * 25.4;   // strip length ≈ 45.01 mm
MAG_W     = 0.512 * 25.4;   // strip width  ≈ 13.00 mm
MAG_LIP_H = 2.0;             // pocket depth
MAG_TOL   = 0.2;             // per-side clearance

// --- Preview Controls ---
SHOW_DISP      = false;
SCREEN_EXPLODE = 0;     // mm to pull display toward X− in preview
SLICE_Z        = 0;     // show only below this Z for cross-section view (0 = off)
SLICE_Y        = 25;       // show only below this Y for cross-section view (0 = off)

// --- Derived Dimensions ---
cav_w     = DISP_W + TOL * 2;
cav_d     = DISP_D + TOL * 2;
case_w    = WALL + cav_w;          // WALL on X+; guide flat face at x=case_w
case_h    = WALL + DISP_T + LIP;
case_d    = WALL * 2 + cav_d;
_guide_or = BEND_R + BEND_WALL;   // guide depth; case extends this far past case_w
_guide_cz    = WALL + DISP_T + TOL - BEND_R;   // guide center Z: aligns guide top with entry slot top
_sweep_half  = 112.5;                           // half of 225° sweep; arms exit at ±_sweep_half°
_exit_x      = case_w + BEND_R * cos(-_sweep_half);   // X of bottom exit arm on inner radius
_exit_z      = _guide_cz + BEND_R * sin(-_sweep_half); // Z of bottom exit arm on inner radius
_exit_span_x = abs(BEND_R * cos(_sweep_half));         // X span from arc tip back to guide center

_cham_xy = CHAM * tan(CHAM_ANGLE);

// Drain holes: punched from Z− face up to just inside the arc bottom
// Y offset keeps hole edges DRAIN_MARGIN clear of FPC cable corners (at ±FPC_W/2 from center)
_drain_depth = _guide_cz - BEND_R + 0.5;          // 1.8 mm solid + 0.5 mm into arc
_drain_y_off = FPC_W / 2 - DRAIN_D / 2 - DRAIN_MARGIN;  // inset from cable corner

win_x = X_PAD + TOL + ACT_X_OFFSET;
win_y = WALL + TOL + ACT_Y_OFFSET;

// Magnetic strip pocket centered on full case length (including guide extension and X_PAD)
_lip_il = MAG_L + 2 * MAG_TOL;
_lip_iw = MAG_W + 2 * MAG_TOL;
_lip_x  = (X_PAD + case_w + _guide_or) / 2 - _lip_il / 2;
_lip_y  = case_d / 2 - _lip_iw / 2;

// -------------------------------------------------------------------
// Display mockup — approximate geometry for preview only
// -------------------------------------------------------------------
module EPD213B() {
    color([0.82, 0.84, 0.80])
        cube([DISP_W, DISP_D, DISP_T]);
    color("white")
        translate([ACT_X_OFFSET, ACT_Y_OFFSET, DISP_T])
            cube([ACT_W, ACT_D, 0.02]);
    color([1.0, 0.85, 0.1])
        translate([DISP_W, (DISP_D - FPC_W) / 2, (DISP_T - FPC_T) / 2])
            cube([FPC_LEN, FPC_W, FPC_T]);
}

// -------------------------------------------------------------------

module rounded_box(l, w, h, r) {
    hull()
        for (dx = [r, l-r], dy = [r, w-r])
            translate([dx, dy, 0]) cylinder(r=r, h=h, $fn=32);
}

module epd_case() {
    _slot_w = FPC_W + 1.0;   // 0.5 mm per-side assembly clearance

    difference() {
        // Case body extended in X+ to enclose the bend guide, X_PAD extends X− end
        rounded_box(X_PAD + case_w + _guide_or, case_d, case_h, CORNER_R);

        // Display cavity — slot opens through X− face, extends full depth including X_PAD
        translate([-0.01, WALL, WALL])
            cube([X_PAD + cav_w + 0.01, cav_d, DISP_T + TOL]);

        // Active area window + chamfered top edges
        translate([win_x, win_y, WALL + DISP_T - 0.01])
            cube([ACT_W, ACT_D, LIP - CHAM + 0.02]);
        hull() {
            translate([win_x, win_y, case_h - CHAM])
                cube([ACT_W, ACT_D, 0.01]);
            translate([win_x - _cham_xy, win_y - _cham_xy, case_h])
                cube([ACT_W + 2*_cham_xy, ACT_D + 2*_cham_xy, 0.01]);
        }

        // Magnetic strip pocket in back face
        translate([_lip_x, _lip_y, -0.01])
            cube([_lip_il, _lip_iw, MAG_LIP_H + 0.01]);

        // Combined cable channel — entry + return, interior walls removed
        // Top is flat at WALL+DISP_T+TOL; floor slopes up from guide exit to cavity wall
        hull() {
            translate([X_PAD + _exit_x - 0.01, case_d / 2 - _slot_w / 2, _exit_z])
                cube([_exit_span_x + 0.01, _slot_w, WALL + DISP_T + TOL - _exit_z]);
            translate([X_PAD + cav_w - 0.01, case_d / 2 - _slot_w / 2, WALL - FPC_POCKET_D])
                cube([0.02, _slot_w, DISP_T + TOL + FPC_POCKET_D]);
        }

        // FPC excess-cable pocket below display floor — cable coils here after the bend guide
        translate([X_PAD + cav_w - FPC_POCKET_L, case_d / 2 - _slot_w / 2,
                   WALL - FPC_POCKET_D])
            cube([FPC_POCKET_L + 0.01, _slot_w, FPC_POCKET_D + 0.01]);

        // Internal 225° bend guide channel
        translate([X_PAD + case_w, case_d / 2, _guide_cz])
        rotate([-90, 0, 0])
        translate([0, 0, -_slot_w / 2])
        linear_extrude(_slot_w)
        intersection() {
            circle(r = BEND_R, $fn = 64);
            polygon(concat([[0, 0]],
                [for (a = [112.5 : -5 : -112.5])
                    [(BEND_R + 0.01) * cos(a), (BEND_R + 0.01) * sin(a)]]));
        }

        // Resin drain holes through Z− face at arc bottom
        // Symmetric pair inset from FPC cable corners by DRAIN_MARGIN so cable glides past
        if (DRAIN_HOLES)
            for (s = [-1, 1])
                translate([X_PAD + case_w, case_d / 2 + s * _drain_y_off, -0.01])
                    cylinder(d = DRAIN_D, h = _drain_depth + 0.01, $fn = 32);


}
}

// -------------------------------------------------------------------
// Render
// -------------------------------------------------------------------
color("#004B49")
    intersection() {
        epd_case();
        cube([X_PAD + case_w + _guide_or + 1,
              ($preview && SLICE_Y > 0) ? SLICE_Y : case_d + 1,
              ($preview && SLICE_Z > 0) ? SLICE_Z : case_h + 1]);
    }

if ($preview && SHOW_DISP)
    translate([X_PAD + TOL - SCREEN_EXPLODE, WALL + TOL, WALL])
        EPD213B();